Gorillas-a Survey Don Cousins - Cambridge University Press
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Gorillas-a Survey
Don Cousins
This survey of the status of the three gorilla races was made in 1974. Part One,
below, covers the western lowland race, and Part Two, to be published in the next
Oryx, will discuss eastern lowland and volcano gorillas.
All gorillas are decreasing in the wild, and the volcano (or mountain) gorilla
Gorilla gorilla beringei is undoubtedly the rarest great ape in the world. Most
primatologists now accept that there are three gorilla subspecies - the two
lowland forms and the one volcano race. The type subspecies, the western
lowland gorilla G. g. gorilla, was first described in 1847 but, due probably to its
shyness and difficult habitat, is less well known and documented than the
volcano subspecies (discovered 55 years later); the sole substantial field study
was completed only in 1968. The eastern lowland gorilla was first described by
Matschie in 1914, from 16 specimens collected by Rudolph Grauer in 1908
and 1910 in the mountains west of Lake Tanganyika, and named G. g. graueri.
For years it was lumped with the volcano gorilla under the general but
misleading name of mountain gorilla, but in 1967, after a scientific study of
skulls in a number of major museums, it was pronounced a distinct subspecies.
The western lowland gorilla occurs in seven countries covering a vast area of
West Equatorial Africa, although the populations occur only in patchy,
localised areas, and vary greatly in size.
Nigeria
It is doubtful if there are any resident populations left in south-eastern
Nigeria, the northernmost extent of the range - although until recently they
certainly occurred around Ikom and Ogoja. But as early as 1930, before many
Europeans had ever seen one, they were described as being in danger of
extinction, and it is now almost certain that they have gone. The Obudu
population, driven from the 6000ft plateau by the establishment of Major
Wally Cranfield's cattle ranch, made their way into the eastern tip of the Boshi
Forest Reserve, where in 1955 and 1956 E. W. March thought that they were
not uncommon, although he never actually saw any, and that they were being
hunted by local people; he was offered gorilla skulls in various villages
surrounding the reserve. He estimated 200 in the reserve, and noted that they
sometimes crossed the border into the Takamanda Reserve in Cameroon. It is
this migration that could be the last hope for Nigeria's gorillas, for since
March's observations Nigeria has gone through very troubled times.
Cameroon
Gorillas are still to be found in small numbers on the north-eastern part of the
Takamanda Forest Reserve in West Cameroon. In 1966/67 Dr Thomas T.
Struhsaker found fresh gorilla nests on the steep slopes between the Obudu
plateau and the lower forest of Takamanda, and in January-April 1968
William R. Critchley estimated that there were at least 25 gorillas in this
reserve but probably not more than 45 or 50. Cameroon authorities believe
that the total is about 60 in the Takamanda and the Obudu plateau combined.
254
Downloaded from https://www.cambridge.org/core. IP address: 46.4.80.155, on 03 Jul 2021 at 21:51:02, subject to the Cambridge Core
terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300015593Gorillas—a Survey 255
At the end of 1976 Julie Webb began a survey of the reserve. Other possible
gorilla areas are Korup in Ndian, Mboko in Manyu, and Bakossi and Korup
in Neme, but these still have to be investigated.
These West Cameroon gorillas are separated by several hundred miles from
their kin in Eastern Cameroon (former French Cameroons). In this region of
over 183,000 sq miles, with an estimated human population of only 5,562,000,
gorillas are confined to the south where the rain forests form a relatively small
part of the country. Even here they have vanished from many parts of their
former range, including the low coastal forests around Kribi, and more
recently the low, humpy, forest-covered hills around Yaounde, the capital.
Even as far south as Mbalmayo they have been hunted to extinction, together
with chimpanzees; in the south-west, around Ebolowa-Mbam-Sangmelina,
the survivors are greatly disturbed and extensively hunted, and the young
captured. In this area two faunal reserves, Dja (526,000 ha, only one guard)
and Campo (330,000 ha, one guard) contain gorillas but offer little in the way
of sanctuary. In early 1974 Dr Alan Dixson saw five young gorillas in the
hands of an animal dealer at Campo, some of which must have come from the
reserve.
The best gorilla areas in Eastern Cameroon are in the remote forests of the
south-east, around Yokadouma, Lomie, Abong-Mbang and Djaposten, but
no population figures are available, or likely to be. To gain an even reasonably
accurate estimate would require much time, manpower and money. The late
F. G. Merfield, who described the frequent hunting of gorillas with poisoned
darts by the primitive Mendjim Mey tribe, observed that gorillas were not
evenly distributed throughout this densely forested region. In 1975 Julie Webb
had to abandon her field study in the Dja Reserve because there were too few.
Gabon
Gabon, south of Cameroon, is the classic home of the western lowland gorilla.
With little more than half a million people in 103,346 sq miles, population
pressures present no danger to the gorillas. But Gabon is rich in timber and
minerals, and already there are plans to open up forest industries in the
interior after the coastal strip has been denuded, and a wide-gauge railway
track is planned to run from Libreville, the capital, to Booue in the hinterland.
However, Gabon forests still contain many gorillas and chimpanzees. In the
northern forests gorillas are to be found around Oyem and Bitam on the
Woleu-N'Tem Plateau, 6000 feet above sea level, and further north around
Minvoul, near the Cameroon-Gabon border, and they appear to be particu-
larly well-established in the north-east corner, in the triangle formed by
Makokou, Belinga and Mekambo. At Belinga the American Bethlehem Steel
Company is mining iron ore. In the Makokou region is the recently created
Ipassa Reserve, covering 15,540 ha; and in Makokou the French have estab-
lished a primate centre, Laboratoire de Primatologie et d'Ecologie Equator-
iale. But although gorillas are to be found only 45-60 miles to the east and
north-east, no field studies are planned as the Director, Dr A. Brosset,
considers the terrain unfavourable for observation. In the Makokou region it
is an offence to kill gorillas, and there have already been several prosecutions.
But sanctions are difficult to enforce in remote villages and among nomadic
groups like the pygmies, who live in symbiosis with the forest fauna.
In 1964 Dr P. H. J. van Bree, of the Amsterdam Zoological Museum, found
Downloaded from https://www.cambridge.org/core. IP address: 46.4.80.155, on 03 Jul 2021 at 21:51:02, subject to the Cambridge Core
terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300015593256 Oryx
that gorillas in the Makokou area frequently emerged on to the open forest
roads but would then retreat into the forest only to circle back to peer at him
through the foliage. The local hunters made use of this natural curiosity,
waiting for the gorillas and then attacking them. In 1965-67 a Peace Corps
worker, Craig Kinzelman, based in the small village of Ekata, about three
miles from the border of the north-east Gabon and the Congo (Brazzaville),
travelled widely with local hunters but only saw live gorillas twice, although he
often came upon traces of where they had fed or nested. For the Bengum and
Mahongwe hunters gorilla was a good kill, but Mr Kinzelman could verify the
deaths of only six to eight during his two years' stay. More recent field workers
at the Primate Centre agree that gorillas are still hunted, and one, Pierre
Jouventin, believes that in 10 years they will be extinct in Gabon. But in the
coastal area around Sette-Cama, and especially in the forest behind, gorillas
appear to be numerous, according to another field worker, Bob Swinehart.
These experiences appear to support Dr Brosset's view that although gorillas
are killed in the Makokou region, they are, thanks to low human population,
in no immediate danger of extinction here. Moreover, the government actively
suppresses illegal trafficking in young gorillas; in January 1974, eleven were
confiscated. Confiscated animals are handed over to the primate centre on the
understanding that none will be exported.
In south Gabon gorillas are no doubt still to be found in the forests around
Lambarene and further east, around Booue. In his early years at Lambarene
Dr Albert Schweitzer treated a number of victims of 'gorilla attacks', but his
successor, 'Papa Lee' Ellerbrock, has informed me that little is now heard
about gorillas and none of the hospital residents has ever seen one. South of
the Ogooue river there are probably more, but there are still large tracts of
uninhabited forest. The Okanda National Park (190,000 ha), created in 1946,
has no tourist facilities, and the contiguous Ofoue Strict Natural Reserve
(150,000 ha) to the south, also established in 1946, is mainly unexplored and
uninhabited and covered in dense humid forest, although some mining
operations are reported. The so-called Region of the Bees west of the Ofoue
reserve, bounded by the Ogooue, N'Gounie and Ikoy rivers and uninhabited
until recently is true primary forest. In 1954 Tom Stacey travelled for fifteen
days there on a semi-circular route, using elephant tracks, from Belleville on
the N'Gounie to Rie on the Ikoy, and found gorillas to be fairly plentiful. But
recent reports indicate that tree-felling is going on for Okoume hardwoods.
In the M'bigou region further south gorillas are reported to be decreasing
due to frequent hunting by the Bachangui, while it is fairly certain that they
still exist in the upper Ogooue region of the northern Okondja district, where
they are hunted by the Samayes. They also survive in the low coastal forest
strip between Port Gentil and Mayumba, a network of waterways, lagoons,
and swamps where crocodiles are abundant. Charley B. Greer Jr, who
captured an infant gorilla in the Port Gentil area in 1951, found gorillas quite
plentiful. It was in this region that Richard Garner, at the turn of the century,
set himself up in a steel cage to observe gorillas and chimpanzees. Two
national parks in which gorillas may survive are the Petit Loango and the
Moukalaba, near Tchibanga. They may also survive in the Lope-Okanda
Game Reserve (150,000 ha), created in 1946. Visiting sportsmen can get a
special gorilla licence from the Minister of the Interior, costing about £250.
Downloaded from https://www.cambridge.org/core. IP address: 46.4.80.155, on 03 Jul 2021 at 21:51:02, subject to the Cambridge Core
terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300015593Gorillas—a Survey 257
There is considerable interest in the western lowland gorilla, and Dr
Stephen Gartlan is responsible for co-ordinating studies in several countries,
including Cameroon, Gabon and Congo. In December 1974 the owner of the
Coucy-les-Eppes Zoological Park, in France, founded the Association for the
Survival of the Gorilla, aimed at establishing an international gorilla reserve
and the creation of artificial islands for gorillas.
Equatorial Guinea
North of Libreville, and close to the Cameroon-Gabon border on the Atlantic
coast, is the former Spanish colony of Rio Muni, now the independent
Republic of Equatorial Guinea covering a mere 80 miles by 125. Here Dr
Clyde Jones, formerly of Tulane University's Delta Regional Primate
Research Centre, and Jorge Sabater Pi, formerly Curator of the Ikunde
Acclimatisation Centre, near Bata, made extensive field studies on the western
lowland gorilla in 1966-68. Sabater Pi had already studied various aspects of
gorilla biology and ecology in Rio Muni, and in 1964 estimated numbers at
about 5000 (later reduced to 2000) in four major population groups: Mbia-
Campo, the Mobumom-Monte Mitra, the Mokula, and the Nkin. All were
seriously threatened in several ways. Rio Muni gorillas were found to utilise
all kinds of forest, frequently raiding plantations for which they were ruth-
lessly hunted. The Fang people's folklore is rich in stories of gorillas, which
they eat regularly. In 1953 the Resena del Parque Territorial del Monte de las
Raices reserve (26,000 ha) was established north of Bata, to protect gorilla and
forest elephant Loxodonta africana cyclotis, but recent reports suggest that
there are no gorillas there. The Mt Alen Partial Reserve is listed as a gorilla
sanctuary, but the planned Parque de Monte del Frio in the south-east never
materialised. The fate of the gorillas in Equatorial Guinea hangs very much in
the balance.
Cabinda
The southernmost point of the western lowland gorilla's range is Cabinda, a
tiny enclave (2794 sq miles) separated from Angola by the Zaire estuary, and
with a population of 50,000. Gorillas appear to be rare and found only in the
north of the colony, around Belize in the Buco Zau region, whence they
migrate across the Cabinda-Congo (Brazzaville) border. In November 1972,
at a meeting at Sa da Bandeiro, Angola (before independence), delegates from
Angola, Mozambique and Portugal agreed that a special reserve for gorillas
and chimpanzees should be set up.
Congo (Brazzaville)
In the People's Republic of the Congo the gorilla's range extends to the former
Middle Congo. In this country of 130,000 square miles, with an estimated
human population of only 870,000, gorillas are reported to be still plentiful.
West of Brazzaville gorillas are to be found around Sibiti, Komono, Dolisie
and M'Vouti. Dr Adriaan Kortlandt, mapping chimpanzee populations in
the Dolisie-Kibangou road area in 1965, found that gorillas were rare in the
forests west of the main road but still abundant in the continuous forest area
to the east.
North-west of Brazzaville gorillas are reported at Zanaga, and 200-300
miles to the north in the riverine forests. Here they are reported to be plentiful
Downloaded from https://www.cambridge.org/core. IP address: 46.4.80.155, on 03 Jul 2021 at 21:51:02, subject to the Cambridge Core
terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300015593258 Oryx
around Ewo, Kelle and Makoua, where they are still hunted by the M'Betis
tribe in a centuries-old feud. Most of the M'Betis hunter's waking life is spent
tracking, surrounding and killing gorillas in organised communal hunts,
preceded and ended by a ritual dance in which gorilla skulls are beaten with
sticks to drive out the evil spirits. Fortunately, weapons are primitive and
usually some gorillas escape. In 1942 the late Armand Denis lived with one of
these tribes for eight months; four years later he found that the gorilla
population was still well in evidence. Further north gorillas are reported at
Quesso, home of the Babinga and Babenzele pygmies, at Impfondo and
Dongou, and about 88 miles south-west of Quesso in the almost inaccessible
Odzala National Park (110,000 ha), mainly secondary forest largely un-
inhabited except perhaps by pygmies.
Central African Republic
In the Central African Republic (234,000 sq miles, population 2,256,000)
gorillas have long been known to exist around Nola, Aboghi and Gounguru in
the south, and even as far north-west as Bambio, where some very large males
have been taken. But the situation today is grim. Some may survive around
Nola, but there is no protection at all and none of the existing reserves
contains gorillas. Dr Kortlandt believes that remnant populations are con-
fined to west of the Sangha river and that some reports refer to chimpanzees.
One theory is that the gorilla population was once continuous from West to
Central Africa, when the climate was wetter and the rain forest more exten-
sive. In 1908 Lemarinel discovered three skulls, all of western lowland gorillas,
at Bondo, in the Uele valley, roughly midway between the existing western
and eastern populations.
Conservation for the Working Man
The views of Jack Mundey, the Australian trade union leader and moving force behind
the conservation-motivated strikes—'green bans'—are quoted in Town and Country
Planning:
'What the hell use is a thirty-hour week to you if you have to spend the other 138,
along with your wife and kids, in a dirty slum in an inner-city area with lousy schools
and no proper hospitals, while ten million square feet of office space stands around
useless in Sydney alone? Work and home conditions should not be so divided—who
wants to live in an environment devoid of a single green tree? The myth that the
environment movement is the preserve of the do-gooding middle class must be
exploded. It is, in fact, the workers who are most affected by the deterioration of the
environment and it is, therefore, up to the trade union movement to give a higher
priority to fighting to improve it.'
Wildlife Haven in Ethiopia
'Ethiopia's richest and finest remaining wildlife country in both variety and number of
species' is J. G. Stephenson's report on the proposed Mago National Park area
covering the eastern rift valley depression, which he visited with a biologist from the
Wildlife Conservation Organisation (WLCO). The area being inaccessible by road,
they had to land by plane in a clearing in the centre and make sorties. The wildlife
includes up to 3000 buffalo, over 500 elephants, 2-3000 lelwel hartebeest, and greater
and lesser kudu; giraffes and crocodiles were 'common'. 'The buffalo encountered on
foot were quite unafraid of humans; one herd of 300 came running up to within 60
yards to satisfy their curiosity'. Tsetse fly has protected the area from development.
Downloaded from https://www.cambridge.org/core. IP address: 46.4.80.155, on 03 Jul 2021 at 21:51:02, subject to the Cambridge Core
terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300015593You can also read
